A method for improving color and the color and odor stability of fatty amides



United States Patent O 3,373,174 A METHOD FOR IMPROVKNG COLOR AND THEQOLOR AND ODOR STAEILETY OF FEET? AMIDES Edgar S. Hammerberg and SydneyH. hapiro, Chicago, 11., assignors to Armour and Company, Chicago, ill,a corporation of Delaware bio Drawing. Filed Dec. 17, 1964, Ser. No.419,222 6 (Claims. (Cl. 260-4il4) ABTRACT OF THE DidCLOfiURE Improvementin color and color and odor stability of fatty amides is accomplished byadmixing an alkalinetype borohydride with the fatty amide.

This invention broadly relates to fatty amides and more particularly toa method for improving the color and the color and odor stability offatty amides, and to the composition produced therefrom.

In the synthesis of fatty amides, especially from unsaturated acids, theproduct obtained has an amber color. Even worse, this undesirable ambercolor is unstable and during storage or use, it darkens. The odorstability of such fatty amides is also not very good and eventually, arank odor is given off. These characteristics frequently prevent use offatty amides, unless drastically purified, in compositions used byconsumers or for the manufacture ofi derivatives which are used forconsumer products.

The curse of an unattractively colored product, or a product whichdarkens or acquires an unpleasant odor with age, has plagued theindustry for a long time. Much effort has been expended, but onlymoderate success has been attained. Since the amides are becoming moreuseful each day, as antistatic agents, antiblock agents, and as slipagents in plastics, for stabilizers in detergents, and as components inwater-resistant coatings, the trade is desperate to find some economicalsolution to synthesize stable fatty amides.

An object of this invention is to provide a novel purification processfor fatty amides.

Another object is to provide an improved purification process for fattyamides which is economical.

Still another object is to provide a purification process for fattyamides which is relatively easy to perform, even by unskilledtechnicians.

A further object is to provide a purification process 1 which improvesthe original color of fatty amides.

A still further object is to provide a purification process whichimparts color and odor stability to fatty amides.

Another object is to provide a purification process which leaves noundesirable residue in the finished amide so that the amide may beeither stored or further processed without subsequent deleteriouseffect.

Other objects of the invention will in part be obvious and will in partappear hereinafter.

The invention accordingly comprises the several steps and the relationof one or more of such steps with respect to each of the others, and thecomposition possessing the features, properties, and the relation ofconstituents, which are exemplified in the following detaileddisclosure, and the scope of the invention will be indicated in theclaims.

It has now been found that amides may be greatly improved in amidecontent and reduced color by subjecting the crude amide to washing witha hydrocarbon to remove free fatty acids, nitriles, colored bodies,etc.,

followed by the addition of a small amount of an alkali metalborohydride or other borohydride derivatives to the resultant wetslurry. The slurry is then dried by stripping solvent therefrom at anelevated temperature. Upon cooling, the cleaned, borohydride-containingamide is flaked and is ready for use as a component in compositions oras a reactant in further synthesis. The borohydride has no deleteriouseffect upon such further use, and in fact, imparts a unique color andodor stability to the amide.

The borohydride that may be used may comprise sodium borohydride,potassium borohydride and quaternary ammonium borohydride. Thehydrocarbon that is used to wash the amide is one having from 3 to 8carbon atoms, and preferably, 5 to 8 carbon atoms so that the washingneed not be done in a pressurized system to prevent volatilization ofthe hydrocarbon. Usually the amount of hydrocarbon used is from two tofive times that of the amide and the washing is performed at roomtemperature. However, additional washes and even temperatures above roomtemperature may be used where the amide is not too soluble in thehydrocarbon, such as with saturated amides.

The invention is more thoroughly described by reference to the followingexamples: I

Example I A seven foot glass column, 1% inches in diameter, is filledwith Armid O flakes (oleylamide). Skelly-solve B (a commercial mixtureof hydrocarbons, B referring to a hexane type with a boiling range of146 to 156 F.) is then added flowing either up or down through the bed.The amide is allowed to soak in the Skelly-solve B for approximately onehour before additional Skelly-solve B is passed through the bed. Afterthe required Weight of Skelly-solve B has been used, the column isdrained, and sodium borohydride added (0.05%, on the basis of weight ofamide charged). The flakes are then transferred to a distilling flask,and the solvent removed at reduced pressure. Yield, color, and percentfree fatty acids are then measured.

it might be noted that when solvent is 'added to the dry Armid 0 fromthe top, the resulting bed is more easily compacted and it takes longerto pass the Skellysolve B through. Because of this, the runs arepreferably made by either filling the column with Armid O flakes andletting the solvent flow upward until the liquid level is above theArmid 0 level, or adding the required amount of solvent to the columnand then adding the Armid O flakes until the solvent is just barelycovering the flakes. The data in Table I illustrates the results thatare obtainable:

TABLE I.SOLVENT WASHING WITH TWO PARTS SKELLY- SOLVE B TO ONE PART ARMIDO IN A 7 FOOT X 1% INCH GLASS COLUMN saturated with water.

1 Free fatty acid as oleic acid.

2 This darkening occurred because the borohydride was removed by thefiltration.

Yields are generally in the range of 88.594%.

General comments.-There is no significant difference in the varioushydrocarbons used as solvents. Results are always better when freshlyprepared, lighter-colored flakes are used. When regular Armid O flakesare allowed to darken in storage, the color is much more diilicult toremove.

Example 11 200 gal. heptaiie is added to a 500 gal. Dopp kettle.Temperature of the heptane is 56 F. This kettle has twelvecounter-rotating arms for mixing. However, no agitation is used duringthe Washing cycle because the soft wet flakes would be destroyed and thearms help to stabilize the bed. 1500 lbs. of Armid O flakes (2.85%F.F.A. and Gardner 4 color) is then added and the bed is leveled. Atthis stage about 3-4 inches of heptane is above the level of the ArmidO. The Armid O is allowed to soak for one hour. The heptane is thendrained from the bottom of the kettle and fresh lieptane is simultaneouly added to the top, maintaining a 4-5 inch level of heptane above theamide. After a total of 400 gal. has been added, the heptane is drainedas completely as possible. 4 lb. sodium borohydride is then added. Thebatch is melted and the remaining heptane is distilled off. After allthe heptane has been removed, the batch is drained, cooled, and packedin 50' lb. fiber drums. Yield is 1409 lbs. with a Gardner color of 1 andfree fatty acid content of 0.1% as oleic acid.

Example 111 Armid (not solvent Washed) having an initial Gardner colorof 4 is treated with 0.05% sodium borohydride and subjected to a heatstability test. The test consists of holding Armid O in a capped 2 oz.bottle at an elevated temperature for at least 18 hours. A sample isconsidered to have passed the test if the final color is not darker thanGardner 10. A control is also run concurrently without the borohydride.It will be found that the final color of the control will be aboutGardner 11-12, whereas that containing borohydride will be about Gardner7-8 or even better.

Example IV In this example, the batch size comprises a 2000 lbs. lot ofArmid O. The amide is solvent-washed, treated with 0.05% sodiumborohydride, stripped of solvent, and drummed. The drums are thenshipped to a distant loca- Table 11 illustrates the type of results thatare obtainable when the amide of the above example is subjected to heatstability test such as described in Example Ill:

TABLE II.HEAT STABILITY TESTS Percent Initial Gardner Temp, HoursRemarks NaBH4 Color Final C.

0.05 2+ 2- 95-100 66 Solvent washed, no air. 0. 05 2+ 2-3 95-100 06 D0.

None 2+ 8-9 95-100 Do.

0. 05 2-3 0-7 110 24 Solvent washed, open to air.

None 5-6 11 110 24 No Wash, open to air.

Vacuum distilled material.

None 10-11 14 110 24 No \vasli.

0.05 1 3 110 24 Solvent Washed.

None 5 9 110 24 No solvent wash.

Example V A 500 gallon Dopp kettle is charged With 265 gallons ofheptane and cooled to -75" P. Then 2000-2200 lbs. of Armid O flakes areadded and the bed is leveled so that a few inches of solvent will beabove the amide. The batch is soaked for 45 min., and then the solventis drained from the bottom at a rate of about 3 gallons per minute.Simultaneously, fresh heptane is added at 65-75 F. to the top of thebatch, maintaining a 2-3 inch level of lieptane above the amide. After atotal of 600 gallons of heptane have been used, the flow of heptane isstopped to the top of the batch, but draining is continued until as muchsolvent as possible has been drained. Atmospheric steam is then suppliedto the jacket of the Dopp kettle until the amide has melted. One lb. ofsodium borohydride is then added and the batch transferred to anothervessel for stripping of solvent.

All slop heptaiie is preferably recovered and reused to effect furthereconomies in the purification process just described.

Examples VI and VII Armid E (Erucic amide) and Armid HT (saturated amidederived from hydrogenated tallow acids) can be processed similarly as inExample I with the following variations in procedure:

(a) The ratio of solvent to amide is preferably 3 parts to 1.

(b) After an initial soak of one hour in the solvent, the first solventis drained and fresh solvent added at the top simultaneously until allthe initial solvent has been replaced by fresh solvent. The batch isthen allowed to soak for another hour. The washing is then continued aswith the Armid 0.

Table III summarizies the data:

TABLE III.SOLVENT WASHING OF AMIDES OTHER THAN ARMID O Ratio 01' PercentInitial Final Percent Percent Solvent Solvent to NaBI-I Gardner GardnerYield EA.

Amide Color 0101' Skelly-solve B 2-1 5 3 9G 2. 1 D 2-1 5 1-2 89. 5 0. 72-1 5 1 97. 3 l. 5 Do 3 2 1 0 2 1 i Nu l i Slliillyt solve B+5% 0 8) 5N11 cc one 3.2-1 15 6-7 86 Skelly-solve B+10% N11 Acetone 3. 8-1 0 2 160 76 Nil 2. 7-1 0. 2 10-11 5-6 87 Nil DO 3 5% 18 7 84. 5 Nil 6Skelly-solve B+10% o 8 0 31 Acctono 3. 8-1 0. 2 9 3 83 Nil Skelly-solveB 4-1 0. 2 0 3-4 86 Nil {The first three lines indicate data run onamide prepared from hydrogenated tallow acids while the remaining datais on amides prepared from crucic acid.

tion to simulate trade conditions. They are then opened and the amidere-melted, filtered, and flaked. The final product has the followinganalysis:

I.V 84.2 F.F.A., percent nil M.P., C 74 Odor Bland Color Gardner 1 5 tol.

The washing is accomplished usually at room temperature, although withthe higher amides, temperatures above room temperature to facilitate theWashing may be used.

The amides to which the technique of this invention has particularapplication are the fatty amides such as the C to C saturated andunsaturated amides, specifically, octyl amide, nonyl amide, decyl amide,undecyl amide, dodecyl amide, tridecyl amide, tetradecyl amide,pentadecyl amide, hexadecyl amide, heptadecyl amide, octadecyl amide,nonadecyl amide, eicosyl amide, henicosyl amide, docosyl amide, octenylamide, nonenyl amide, decentyl amide, undecenyl amide, dodecenyl amide,tridecenyl amide, tetradecnyl amide, pentadecenyl amide, hexadecenylamide, heptadecenyl amide, octadecenyl amide, nonadecenyl amide,eicosenyl amide, henicosenyl amide, doscosenyl amide, octadecadienyl,amide, octadecatrienyl amide, eicosatetraenyl amide, and docosapentenylamide, or mixtures of amides such as would be derived if the naturalfats and oils were amidated and particularly the amides derived byamidating tallow, coconut oil and soybean oil.

The borohydrides which are operable in the technique of this inventionare sodium borohydride, potassium borohydride and quaternary ammoniumborohydride. The concentration ranges vary between 0.05 to 0.2% byweight of the amide.

It will thus be seen that the objects set forth above, among those madeapparent from the preceding description, are efficiently attained and,since certain changes may be made in carrying out the above method andin the composition set forth without departing from the scope of theinvention, it is intended that all matter contained in the abovedescription shall be interpreted as illustrative and not in a limitingsense.

It is also to be understood that the following claims are intended tocover all of the generic and specific features 3 of the invention hereindescribed, and all statements of 6 the scope of the invention, which, asa matter of language, might be said to fall therebetween.

Now that the invention has been described, what is claimed as new anddesired to be secured by Letters Patent is:

What is claimed is:

1. A process for improving the color and odor stability of fatty amidescomprising admixing 0.05 to 0.2% by weight of an alkaline-typeborohydride with said fatty amides.

2. The process of claim 1 wherein said borohydride comprises sodiumborohydride.

3. A process for improving the color and the color and odor stability offatty amides comprising Washing said fatty amides with hydrocarbons, andthen subsequently admixing 0.05 to 0.2% by weight of an alkaline-typeborohydride with said fatty amides.

4. The process of claim 3 wherein said borohydride comprises sodiumborohydride.

5. A color and odor stable fatty amide composition comprising at leastone fatty amide admixed with 0.05 to 0.2% by weight of an alkaline-typeborohydride.

6. The composition of claim 5 wherein said borohydride comprises sodiumborohydride.

References Cited UNITED STATES PATENTS 3,159,276 12/1964 Moore 206-843,207,790 9/1965 Glew et al 260584

